Question: $ { \left[\begin{array}{rr}{3} & {1} \\ {-2} & {-1}\end{array}\right]+\left[\begin{array}{rr}{4} & {-2} \\ {0} & {0}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{3}+{4} & {1}+{-2} \\ {-2}+{0} & {-1}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{7} & {-1} \\ {-2} & {-1}\end{array}\right]}$